In millimeter wave (mmWave) communication systems, high data throughput may be achieved through directional wireless links between transmitting and receiving devices. As an example, an access point (AP) may provide high data rate traffic to multiple user stations (STAs) over directional wireless links that are substantially isolated from one another. In some cases, communication on directional wireless links may include directional transmission of a beam from the transmitting device along with directional reception of the beam at the receiving device. A beam alignment process for the directional links may be used to improve performance, to track mobile devices in motion, or to help deal with changes in the physical environment in which the devices are operating.
As part of the beam alignment process, some of the packets sent over the link may include a receive training sequence to enable the receiving device to train it's receive direction for the link. In addition, other packets may include a known transmit training sequence that may enable the receiving device to select or provide feedback about the transmit direction for the link. Although the use of the training sequences may cause significant overhead on the link, such a beam alignment process may be increasingly necessary in systems that support outdoor operation or expect high mobility, such as next generation mmWave systems. In addition, current and future mmWave systems may need to support many directional wireless links simultaneously, for instance between an AP and multiple STAs. Thus, there are general needs for systems and methods for simultaneous high-speed multi-user beam tracking.